FIRST PERSON

Is it true? Well, '50/50'

The screenplay based on a real-life experience is fictional -- not that anyone believes that.

Will Reiser put his life experience into his script for "50/50." (Al Seib, Los Angeles Times )

'50/50" was the first feature script I ever wrote. The reason? When it came to writing, there was nothing exceptional about any of my ideas. I'd always aspired to write movies like the very ones that inspired me: "The Apartment," "Harry and Tonto," "Harold and Maude." Comedies that are not only funny, they're tragic and they're human. But those movies are experiential meditations, and when I was in my early 20s, the only thing I knew to write about was what it's like to be single, horny and terrified of women.

Then, at 25, I was diagnosed with cancer and everything changed. At the time, I was reading Neil Simon's autobiography "Rewrites," and I came across a passage where Simon describes his inspiration for "The Odd Couple"; apparently Simon's older brother Danny, a recent divorce, had moved in with a close friend, also a divorce, and the union was anything but harmonious. One was a control freak, the other a slovenly misanthrope. Two men, total opposites, both reeling in the tragedy of their failed marriages, depending on each other for support as they feuded over the hygienic state of the bathroom -- that was all he needed to create one of the single greatest pieces of comedy.

For The Record Los Angeles Times Friday, December 16, 2011 Home Edition Main News Part A Page 4 News Desk 1 inches; 48 words Type of Material: Correction Celebrity photos: In the table of contents for the Dec. 15 edition of The Envelope, the photographer credits for two pictures were incorrect. Los Angeles Times staff photographer Al Seib took the photo of Will Reiser and Times staff photographer Robert Gauthier took the photo of Steven Spielberg. For The Record Los Angeles Times Thursday, December 22, 2011 Home Edition The Envelope Part S Page 3 Entertainment Desk 1 inches; 48 words Type of Material: Correction Celebrity photos: In the table of contents for the Dec. 15 edition of The Envelope, the photographer credits for two pictures were incorrect. Los Angeles Times staff photographer Al Seib took the photo of Will Reiser, and Times staff photographer Robert Gauthier took the photo of Steven Spielberg.

Simon's lesson in mining his own life was a revelation, for here I was living my very own tragic comedy. Suddenly, I could write about what it's like to be single, horny and have cancer, which I later learned equals a movie.

But just like "The Odd Couple," "50/50" is a work of fiction, inspired by real life. My intention was not to draft an autobiography and rehash old wounds; rather it was to write the best movie I could. That said, "50/50" is tethered to my own experience, but as I've come to learn, that line I drew between fact and fiction is far less distinguishable than I thought.

While writing the movie, I knew that Adam Lerner's (our protagonist's) journey would embody my own, but I wasn't trying to turn him into me. And yet, since the film's release, I've had dozens of close friends and family members mention that Joseph Gordon-Levitt's performance is an "astonishingly uncanny portrait" of me. I've been told he "nailed my mannerisms" and "even my posture." When people mention their favorite scenes, they usually include me in that description -- "the moment when you're in the car, and you go mental and have your emotional breakdown." But that isn't me. Or is it?

How do you explain that a character isn't you when he speaks and behaves exactly as you do?

In almost every interview Seth Rogen's given, he's had to explain that, yes, just as in real life, we are best friends, and, yes, Kyle is an extension of himself -- however, in no way is he a misogynist like Kyle!

During post-screening Q&A's, I've disappointed viewers, revealing that no, Seth and I didn't use my cancer to tempt women into bed. And no, I didn't really fall in love with my therapist (in reality, my therapist was in her 50s -- I'm slightly mortified to know what she thinks).

My father is what I can best describe as an eccentric daydreamer. He does not, however, suffer from Alzheimer's as Adam's father, Richard, does in the film. Regardless, my real father spent the night of our premiere being coddled as people spoke to him slowly and deliberately, as though he were mentally impaired. My sister, spared from any characterization at all in the film, has had to answer the question, "Why wasn't there a sister character? Are you two just not very close?"

The one relationship in the film that most closely depicts real life is the one between Adam and his mother, Diane (Anjelica Huston). I love my mother, but just as Diane does to Adam, my mother drove me absolutely insane while I was ill. And like Adam, I pushed her away, rebelling against her primal instinct to smother me. I remember thinking, "If the cancer doesn't kill me, her smothering will."

At the time, I had little perspective to understand what it must have felt like for my mother to bear that kind of rejection, which would have been tough for anyone, let alone a mother helplessly watching her son suffer. So for the last two years, as she's cheered me from the sidelines, I sensed my mother silently fearing her depiction in the film -- worrying she'd be portrayed as the unbearable mother I pushed away. Not only did her son rebuff her, millions of people were now going to write her off as annoying and incapable.

The day finally arrived when Sandy Reiser would meet Diane Lerner -- Sept. 12, the "50/50" premiere in Toronto. I sat next to my mother, more concerned with her reactions than the audience's. During the dinner scene -- in which Adam reveals he's sick and Diane has an emotional breakdown after he refuses her help -- my mother leaned over and whispered, "Is that the worst of it?" "Oh crap," I thought, "I've humiliated her." She sat silently for the next 40 minutes, until the moment right before Adam goes in for his surgery, when she grabbed hold of my hand.